Hydraulic control system



Feb. 12, 1957 J. H. PROVINCE 2,780,950

' HYDRAULIC CONTROL SYSTEM Filed sept. 17, -1954 s met-sheet 1 Feb.- 12,195.7 J. H. PROVINCE 2,780,950

HYDRAULIC CONTROL SYSTEM Filed Sept. 17. 1954 6 Sheets-Sheet 2 9o 55 leo56o 87o "Mo '3S F/G. 3. O 7

|63 INVENToR.

v J. H. PROVINCE |67 soa' |71 lee 9o@ By 54@ no H M0* ATTORNEYS Feb. 12,1957 J. H. PROVINCE 2,780,950

l HYDRAULIC CONTROL SYSTEM Filed Sept. 1'7, 1954 6 Sheets-Sheet 5INVENTOR. J.H.FROVINCE BY s# ATTORNEYS Fell 12, 1957 J. H. PROVINCEHYDRAULIC CONTRO;d SYSTEM 6' Sheets-Shea#I 4 Fi1e`d Sept. 17, 1954 o 5nw w 7.. 2

Feb. 12, 1957 J. H. PROVINCE HYDRAULIC CONTROL SYSTEM 6 Sheets-Shea?I 5Filed Sept. 17, 1954 INVENTOR. J H PROVINCE AT TORN EYS Feb. I2, 1957 J.H. PROVINCE HYDRAULIC CONTROL SYSTEM Filed Sept. 17, 1954 6 Sheets-Sheet6 AT TORN [YS United States ate 2,780,950 Ice 'lhented i Feb. 12, 1957Appuetin 'septemer 17; i954; serial No; 2455,694 2s Ciiis. (Ci. 531;'53)

This invention relates' toa 4control system for hydraulic pumps. inanother aspect it relatesto a hydraulic system toaotuate a pipeto'ng Inanotheraspect relates to pneumatic clutch system. In anothe'rspect itrelatesfto' a rotary air coupling. Iii still another aspect itrelate'sto improved pipe tong in oil well servicing operations it commonpractice to' obtairrthe poweu'eeded to. operate thehoist'ing winch,tubing tongs and otheruuits'ffrxn a truckrnotor. Heretofore,` poweroperated tubing tongs h'aVeus'ually been energized pneumatically. Such tv g's require alarge supf p ly of compressed air which necessitates theVinstallation of a large air compressorbecause-the compress c'ujvsupplied for control purposes does nothave suicient capasity. Thisequipment is useful only iiioperating the tubing tfnjrgs.I However,modern well servicing units often ein; ploy hydraulic purnpsfor theoperation dfderrick's and' other equipment. Thus', a suitable hydraulicpump nor: rnallyis available on a servicing rig. For this r'eason Ipropose tooperart'e the tubing' tongs'hydra'ulically.

Tub'ing tongs are provided with pipe gripping jaws whichfengage thepipein one direction of rotationl and disengage in the opposite direction.These jaws can bereversedin vsome instances to allow th`e pi 1 e to be dr'i'vn in yeither direction. A slot i'su'sually provided in theotatingheadof the tong to all ow the tong vto beplaced on thapipe andrmQYed fli1r0z This Slot must be Cleii: tered with a` 'correspondngslot' in thejanieof thfeiton'g in order to apply or removethe tong. tis,ofcourse, des le that this centering operation be performedautomat1cally. In accordance with thepresent invention a novel centeringvalveajssernbly is provided/,

The hydraulic pump employed -to energia" th'etubiu'g' tongsjn'onnally isdriven bythe sametruck motor whichr energizes the hoisting'winch.llfliscr` s certairi dicu1ties' because the rriotor Inustbe opera at a'cons ablyhigher speed when operating the winch than' heu coupled to thehydraulic -iiiotor. Ir order t'qp nl ihe hydraulic motor trom beingdriven' atari excessivespeed Whe the engine s ,drivins.,th Winch; apueuma'ti'cially Operated Clutch System prsyiddin cordnic ,with thisinvention to disengage the'driveshaft ,of Ythe truck from the hydraulicmotor 'when the speed of the motor shaft.

une i 2 `met beds dvneelwild features '91?. f li'sviiviition shouldbecome 4ap ent ufrom thefollowing tailed description gtaken' inconjunction with the accompallxingdrawsinwhh; Figure 1 is a scheinaticrepresentation of the co rl thisinvenition; Pi t@ .2 is .adta11t1v.@W-afa tirstembsdf the pneurnaticallyv perated clutch mechanismincluding valve employed inl conjunction they tubing to digure is adetailed View,ofharsuitabletubin tong which can be used in the controlsystem of this inven- On; ,f -fif x5- 1f [El igureis a detailed view ofa second embodiment of theaircouplingtand Figure 7 is na detailed Viewof a third embodiment of the aircoupling. i i Referringnowtothe .drawingin d etail vand to igure l in particular thereis shown a truck motor 1Qwhich is einpl'oyedto energiae `awell servicing unit. The speedfat whichmotor lil operates is controll ed by abutteryvalve the carburetor il.tThis v alye can be positioned by@ pneu'rnatically operated controller1`3. Controller 13, h ich can be of the formiillustrated in Figure 1'6of,l S Pa te n t 2,`6 43 ,'093, is erg'izfed by a sourceof air pres esupplied from s torage tank 14 Tank `'s j tunecteid to an aircompressor, not s l'n'rvvn,I aline l1S. `Iflfliiie 1 6 extends betweentank, 14. afldfth. il 0f ,aihftl valve i The first air inlet incontroller 1 3y iscoune I d totan il'i through a lin e lshaviug" athree-way soleil id V lv 2531s C Qnolldby a 'solenoid Z4 Wllh 1 Senergized f rQm vsiltagfgsjui 25,.. Qriftrlliulsf voltagesourceZS is,.cor'inectedto ground as is, one ter; Ininal o f so1e'noid-24.' TheV'seoutl terminal of voltage source ZSisCOunectedto the second terminalofis oid 24 rbya lead 27 hay ing aswitchfZS therein, A line sffilmaflesbetween ,velyaz and ffiwsvhefe- Infhe absence of powerbeing supplied to[solen d 24, lined? communicates through valve 23 with tank 1 4. Whensolenoid 24 .is c uerg'ized,` line 1`9 communicates throughv1ve23with'1in e 2 z.

The drive ShatOfengue 1 0 is Connected t'houw suitable power. tal' e'o129 and ajshaftSQ tooue mem; bei of a clutch The second member ofclutchiis Cerl'ncfd by ashaft 32 we hydfauliapvmp. .Clutch 31 iS saged by the,vanalist@ H911 0f pneumatic Dfllsift.; 'eeto through' a coupling Sawhichilsfounfed @Shaft 3 2. Air pressure for energizing elu't'cli 3 1 is'supplied `from as'econd'st'orage tanli whicli'is connected toline 15 aliner 3 6 having a pressure reducing' va'flv,e 37y yt Thepressureinvtank 3'5 i s less than the pressure vin t Tank 35 is connected tocoupling 3`4 by aline hav a solenoid operatedthree-wayva1ve 3 9, anoilera' quick feles'rw .4 1 thre- Yah? 39 b'y a sblii'd. ''.whlichhas'sneitminal sounested. ground. The s`econdqtermina1n-of solenoil 4 3ne'cted to ,th'eseco'n'd terminal oi' 'tage source 2 5 b: alead44lwhich` has manually operated `sgwitch, 46 da pressure operatedswitch 47 therein u SWitch k47 `isfconffw. trol'led by thepressureinline which'isfapplied through a line 48, pressure above apredetermined value ppeniugl electrical switch 47 and below said valueclosing said l., l n *y rml.; uw g z Quick 'release valve'41 ina staudard 3 way vquick t e lease valve, mere fflly u1u" "'-iapii p l of'VVthe lBendiXWes tiigho'u'se MMaintenance Marinai JSLW 1116 published in1952 by the BendioWestinghouse Automotive Air Brake Co. This valve 41 isnot necessary to the operation of the system and may be dispensed with,its main purpose being to allow air to vent to the latmosphere throughopening 41a (when open) faster than it could vent through line 38b,oiler 40, line 38a, valve 39 and vent line 39a, thereby allowing clutch31 to release quickly, without slipping, and frictional wear during suchslipping. Valve 41 consists of a body having a chamber (not shown) withan air supply inlet and preliminary exhaust line 38h, `a quick airrelease outlet 41a disposed opposite 38b, and a line 38e connecting oneside of the chamber to clutch 31. There is a valve seat around 38h and41a in the chamber, and a valve head having a flexible annular rim isbiased by a spring toward 38h. When pressure in 3817 is high, the valvehead closes 41a and air from 38b passes the flexible rim into 38 toengage clutch 31. When pressure in 31 balances said high pressure in38h, the exible rim closes 38h, while the valve head closes 41a. Whenpressure in 3811 falls below that in 38C, the valve head unseats, laidedby the spring, opening vent 41a to clutch line 38C allowing quickrelease of air to the atmosphere. When high pressure returns to line38b', the valve head closes 41a and the air passes the iiexible rim into38C repeating the cycle.

Valve 41 is not necessary, and may be eliminated, as when either one ofelectrical switches 46 or 47 is open solenoid 43 moves valve 39 toconnect line 38a to vent line 39, and air is released to the atmospherethrough line 38h, oiler 40, line 38a, valve 39 and vent line 39a, whilevalve 39 closes line 38 from tank 35. When both switches 46 and 47 areclosed solenoid 43 moves valve 39 to close vent line 39a and connectlines 38 and 38a, supplying air under pressure from tank 35 to valve 41and line 38C to clutch 31 to engage said clutch.

The inlet of pump 33 is supplied with hydraulic iiuid from an oilstorage tank 511 by a line 51 having a filter 52 therein. A fluidleakage line 49 returns to tank 50 from pump 33. The outlet of pump 33is connected by a line 53 to a first port 54 of -a valve 55 which isdescribed in detail hereinafter in conjunction with Figure 3. A secondport 56 of valve 55 is connected to the first port 57 of a second valve58 by a line 59. A second port 60 of valve 58 is connected by a line 61to the first port 62 of a third valve 63. A second port 64 of valve 63is con# nected by a line 66 to a uid opening 69 of a hydraulic motor 67.Motor 67 is connected to a gear box 68 which drives the tubing tongillustrated in Figure 5. The second fluid opening 70 of motor 67 isconnected by a line 71 to a third port 73 in valve 63. The fourth port74 in valve 63 is connected by `a line 76, a check valve 77 and a line78 to the third port 80 of valve 58. The fourth port 81 of valve 5S isconnected by lines 82 and 83 to oil tank 50. Ports 80 and 74 ofrespective valves 58 and 63 are connected by line 78, a centering valve85 and line 76. A third port 87 in valve 55 is connected to a line 88 tosupply hydraulic uid to other apparatus, not shown, which may beemployed on the rig. The iiuid supplied by line 88 is returned through aline 89 which is connected to return line 83. The fourth port 90 ofvalve 5S is also connected to return line 83 by a line 91. Line 59,which connects ports 56 and 57 of respective valves 55 and 58, isconnected to tank 50 by a line 92 having a pressure relief valve 93therein. The connections between the ports in valves 55, 58 and 63 aredescribed hereinafter.

Air coupling 34 and clutch 31 Iare illustrated in detail in Figure 2.The purpose of coupling 34 is to introduce air from line 38 of Figure linto a passage 100 in shaft 32. This air pressure in turn actuatesclutch 31 to connect shafts 30 and 32. Coupling 34 comprises astationary annular housing 101 having an inlet port 102 whichcommunicates with line 38. The center portion of housing 101 is providedwith an inwardly extending ange 103 against which is positioned a pairof ball bearing assemblies 105 and 106. These ball bearing assembliesengage stationary housing 101 at their outer edges and rotatable shaft32 at their inner edges. M'ating rings 107 and 108 are fitted aboutshaft 32 in engagement with respective bearing assemblies and 106.Sleeves 110 and 111 enclose shaft 32 and engage respective mating rings107 and 108 at their inner edges. A rst O-ring 114 is positioned betweensleeve 110 and mating ring 107, and a second O-ring 115 is positionedbetween sleeve 111 and mating ring 108. Sleeves 110 and 111 are locatedin position on shaft 32 by respective retaining rings 112 and 113. Afirst sealing assembly 117 is positioned between housing 101 and matingring 107. This `assembly is held in position by a retaining ring 118 andis sealed to housing 101 by an O-ring 119. A second sealing assembly 120is positioned between housing 101 4anti mating ring 108. This secondassembly is held in position by a retaining ring 121 and is sealed tohousing 101 by an O-ring 122.

Sealing assembly 117 only will be described in detail, it beingunderstood that sealing assembly 120 is of like construction. Assembly117 comprises an annular shell 125 which surrounds sleeve 110 but isspaced therefrom to provide a clearance. Shell 125 engages an annularinsert 126 at its inner end and retains this insert in slidable sealingContact with mating ring 107. The engagement of insert 126 with mating.ring 167 provides the rotary seal. An annular cup member 127 extendsbetween shell 125 and housing 101. Positioned within cup member 127 isan annular packer 12S which is retained against cup 127 by an expander130 and an annular spring 131.

Housing 101 and bearings 105 and 106 define an annular chamber 133between shaft 32 and inlet port 102 of housing 101. A passage 134 isformed in shaft 32 between passage 100 and chamber 133. Thus, the airpressure in chamber 133 is introduced into passage 160 irrespective ofthe relative position of shaft 32 and inlet port 102.

A spider 135 is rigidly attached to the end of shaft 32 as by a key, notshown. A fluid passage 136 is formed in one of the ribs 137 of spider135. The inner end of passage 136 communicates with passage 100 througha radial passage 138 in shaft 32. A conduit 140 `communicates with theouter end of passage 136. A flywheel 142 is rigidly attached to the endof shaft 30 adjacent shaft 32 as by a key, not shown. The adjacent endsof shafts 30 and 32 are spaced from one another. An annu lar drum 143 isattached lto spider 135 by bolts 144 and extends outwardly to encloseflywheel 142. The annular space between flywheel 142 and drum 143contains a pneumatically operated brake device 145. This device can bein the form of an expansion member formed of a sturdy fabric 146 havinga rubber liner 147. The interior of liner 147 communicates with a port148 in drum 143 which is connected to conduit by a conduit 149. Aplurality of brake shoes 150 is attached to member 146 to enclose ywheel142. In the absence of air pressure being applied to the interior ofliner 147, brake shoes 150 are retained out of engagement with flywheel142. However, the introduction of air pressure into liner 147 results inan expansion of member 146 so that brake shoes 150 imly engage flywheel142. Shaft 32 then rotates with shaft 30.

Valve 55 is illustrated in detail in Figure 3. This valve comprises abody having a central passage therein. A shaft 161 is positioned in thepassage of body 160 and is pivotally attached to an adjusting handle162. The ends 163 and 164 of shaft 161 engage body 160 in a fiuid tightt by means of respective O-rings 166 and 167. The center portion 168 ofshaft 161 is of the same diameter as the central passage through valvebody 160. The portions and 171 of shaft 161 between portion 168 andrespective ends 163and 164 are of smaller diameter than the centralpassage. A plurality of annular recesses 90a, 87a, 54a, 56a and 90a' isformed in body 160 surrounding the central passage. Recesses l90a and90a are in communication with port so.. neeesses stuitte una semestricommenceront `with.rospo'ctive .ports ,54;87 and t56; not v'shown inyFigui-e 3. .Valve 55 normall'yis biased by -feans not shown, in theposit-ion illustrated.

When shaft 161 `occupies the illustrated central sposition, all voftherecesses are in communication with one another. If handle162 is rotatedclockwise about pivot point 4173i, sh'aft 161 is moved tojthe left Osuchlthat end 163 blocks recess 9021 'and portion 168 of shaft 161 isdisposed between recesses 54a and 56d; At this position, recesses 54da`nd. 87a are. in `co'rnrnnnicati'on 'as are reesses 56a and 90a'.'Ifhandle 162is moved counterclocltwise about pivot point 173, shaft 161is rnoved t'o the right such that end 164 blocks recess '90d' andportion 168 is disposed b'etveen recesses 544 and 87a. At this .secondposition;4 recesses 56d land 54a are in com'- munieation as arefecesses'87r1 and 90a'.

Valves 58 and, 63 are 'similar to valve 55 except they vare ,providedwith detehts to retain shafts 163 normally at either end positions.

Centering valve 85 is shown in Figure 4. This valve comprises a hollowcylindrical bdy 180 having a cylin- -ler' 181 triountedthereon. vA coverplate 182 is fitted to the top of .cylinder 181 and the three membersare held in assembled position by `screws 183. VCylinder 181. isprovided with a chamber 184 adjacent plate 182. An Qfring 185 ispositioned between cylindei 181 and plate 182. A longitudinal passage186` is formed in cylinder 181 between chamber 184 and a first port 188which receives line` 78. Port 188 also communicates with the interior ofcylinder 181 through a passage 190. A second port 191 is provided incylinder 181 opposite port 188. Port 191, whichreceives line 76; isconnected to the interior, of lcylinderv 181 through a passage' 192.Passages l90an`d 192 are blockedy from-'one another .when

a piston 193 occupies theillust'tted position incylinder 1811.- Piston193' is providedl with an' annular recess 1-94 vso that passages 190 and192 are in communication when piston 193 occupies a second lowerposition. A p'air of sealingv rih'g's 196 and 179 is mounted on piston193. The lowerend of piston 193I engagesA ay secohd pistn 200 containedwithin body 180. Pistoni' 200 islattached to a plunger 201' by a s`cew202' Plungerl 201 extends downwardly, beyo`r1`df the lower' edge of body18h and has a roller`203 attached thereto Bya pin 204; A' compressionspring-,205l is-k positioned between valve body 180 and piston 201 toexert a force which te'nds to raise piston 200jwithin valve body, 180:`Roller 203' is raisedv wheny engaged-by aiy cam `2.06 which' is mountedon the tubing tong. illustrated' in .Figure 5f,

The tubing tong 209 illustrated in Figure isa conL vention'al powe' tongwhich is'v adapted t' be energized lay-hydraulic' notor 6'7` inaccordancewith'thisA invention. Tong209` is used to-screw and unsc'fewthreaded sections rofpipe," one' of which' is illustrated at 210. This'power tong comprises a base' 211 upon'- which is attached acove'r, notishown,v by: a plurality; of. bolts 212. Posi- 't-'ionedi within base 211is ay ring' 2-13ha'ving a 4 side'eitrance opening 214i definedl byparallel'l 'walls 21'6l and i217. Ring 213 is rotatably supportedV onbase 211' by a plurality of grooved rollerst 218. y

Ring 21:3 isrotatedinl frame 21d-"by means which include a sproelet220ffthat isA securedtojiihg 213 by screws 221i.- Sprock'et 220- is'also provided with`- an en'- .tranc'e' opening' whichxisl aiigned withopening 214 inring .213.- Sprocket-220fis`driveng byfa chain 222 whichAis woundabout idler sprockets 223' and" 224 andv a'v driv ingsprocke'tfZ-ZS'.' Sprockets 223 and224 are' n'iounted on'zr'espectiv'e"sliafts 227 and' 228: Driving/sprocket 225 `is-rnounted.ongafslilrdportion of' a'powr shaft 30` so that sprocketl225'- rotates with@ theshaft A- rstdri'ving: gear.- 231-'is11nountdY on' drive shaft 232. A3second" driving.; gear' 233'; is? also mounted on-V v56 vided 'forshifting g'eai 236 '.eilgientent with driving gear 231 and for shiftingge' 4235 info engagement driving gear 233. This means includes'ayolr'ex240whch is carried 'on a 'pivotally mounted yok "shaft241 that 5extends outwardly through base 211: Shaft 241 is provided with a pair ofactuating levers 242 onto'pposit'e sides of thebase". Driving shaft 232is vcnpled to l'gear box 68 of Figure 1 which is rotated by hydraulicmotor 67'., f

The introduction. of hydraulic .fluid int-o motor` v67 'causes rotationof 'shaft 232. Shaft 230 can be `driven from shaft 2732 at a -low speedthrough 'gears 231 and v 236 or at a high speed through gears 233 and235'. The shifting of gears is accomplished by rotating handles 2 4'2.Rotation of shaft 230 causes the..spro'cket Wheel 22S to drive chain 222to turn i'in'g 213: v l

.Means are provided on ring 213 to. giip pipe 210. 'These means includecarrier 245 on which pip' grip'- ping jaws 246 and 247 are mounted.Carrifei 245 is positioned coaXiaIly of ring 213 and i'sfree' to 'turnwithin the ring; Jaw `247 is fiired to carrier 245 by an at# taching pin243 and is provided with a iSair of spaced pipe gripping dies 248 and249. Jaw 246 carries a removable pipe gripping'die 250, A .b'rake' 251exthds upwardly from carrier plate 245 and is 'adapted to' be contactedVby a stationary brake band' 252 which is secured tothe cover by meansnot sh'own. The function of band 252 and rim 251 is to retai'd rotationof carrier 245.

After a pipe joint has been tightened- 'it is necessity to'fwitlidrawthe tong from the pipe; This' requiies' that side opening 214. in ring213 be aligned with the entrance opening in base 211. Since thethre'ad's of the pipe joint may become tightened at any random position;means must oe provided fr tui-ning r'in'g- 2'13 in a' erse di'-re'ctio'n to bring about alignment' of th openings.v is accomplished inaccordance with the present invention by .centering valve 85' whichcooperates with' cam 206 which is' mounted on ring 213 opposite' tleentrance' open? ing. Valve 85 is' positioned immediately above' carriY206 as shown in' Figure 4.A

Theoper'a'tion of the hy'r'drau'lit:controlV syste'ni` of this inventioncan be explained' with reference to' liigu're l'., When it is4 desiredto operate any of the hydraulic aci tu'ated units,l switch" '46' is'closed' to complete' a" circuit through solenoid 43. This" .opensvali39' suchmtli'at' the air pressure in tank 35' is applied through l'in'38, rotary coupling 34 and shaft 32'fov clutch 31. Asshown in Figure 2,the application of air pressure'to clutch 31 results i`n drinnl 143being coupled to ilywhel 1:42 isuch that the two members rotatetogether. ijn thisI manner shaft 32: is rotated? with; shaft 30' to'drive pump 33'. Switch 28 can then'y be closed to' complete' a circuitthroughy solenoid 24. This 'opens' valve 23' so that' the' airpressure'ifroin line 19`i's` vented throiigh line 22. *Conlh troller1^3/is 'set-so that` with` switch' 46'cl'o'sed ahd 'switch 28 open, themotor 10`operat's'at a orni'al idlev speednd drivesy puirp 33 at1 aspeedy suii'cientl to supply' power fluid for` the operationv-olf thosehydraulic' units' which require comparatively' si'nallv amountof tid,such afs derrick raising mechanism, sucker rod' tongs,

operate any oftheauxiliary equipme trnot slown',"va1ve" vsure is thentransmitted .to line 88 and is returned to tank through lines 89 and 83.c

n In order to energize the power tongA in a forward direction, valve isset such that ports'54 and 56 are in communication as are ports 87 and90. Valve 58 is set such that ports' 57 and 60 are in communication asare ports and 81. Valve 63 is set such that ports 62 and -64 are incommunication as are ports 73 and `'14. Under these conditions, the uidfrom pump 33 passes through line 53, valve 55, line 59, valve 58, line61, valve 63 and line 66 to the opening 69 of motor 67 Fluid is returnedto tank 50.from motor 67 through opening 70, line 71, valve 63, line 76,check valve 77, line 78, valve 58, line 82 and line 83. After each pipejoint has been tightened, it is necessary to remove the tong from thepipe. As previously discussed, ring 213v of the power tong may bepositioned such that the outlet opening therein is not aligned with theoutlet opening of base 211. Alignment is accomplished by reversing valve58 such that ports 57 and 80 are in communication as are ports 60 and81. The fluid under pressure then passes from line 59 through valve 58and line 78 to the inlet port 188 of valve 85, see Figure 4.

Fluid is transmitted through passages 190 and 186 of valve to thechamber 184 above piston 193. Piston 193 initially occupies theillustrated position due to compression 205 even though roller 203 doesnot rest upon cam 206. It should be observed that roller 203 rests uponcam 206 only when the opening in ring 213 is aligned with the opening inbase 211. The introduction of uid into chamber 184 results in piston 193being displaced downwardly until the annular recess 194 communicatesbetween inlet passage 190 and outlet passage 192. The uid under pressureis thus transmitted through valve 85, line 76, valve 63 and line 71 toenter motor 67 t through opening 7 0. This causes motor 67 to move inthe reverse direction until cam 206 is moved into engagement with roller203 at which time piston 193 is moved back to the position illustratedin Figure 4. The piston then blocks the opening between passages 190 and192 and no additional uid is pumped into motor 67. At this point, theopening of ring 213 is aligned with the opening of base 211 so that thepipe can be removed. When motor 67 is operated in the reverse direction,iluicl is returned to tank 50 through line 66, valve 63, line 6l, valve58= line 82 and line 83.

When the power tong is employed to unscrcw pipe sections, valve 58 ispositioned such that ports 57 and 60 are in communication as are ports80 and 81. Valve 63 is positioned such that ports 62 and '73 are incommunication as are ports 64 and 74. The uid under pressure is thentransmitted from line S9 through valve 58, line 61, valve 63 and line 71to port 70 of motor 67. Fluid is returned to tank 50 through line 66,valve 63, line 76, check valve 77, line 78, valve 58, line 82 and line83. In order to center the tubing tong when operated in the reversedirection, valve 58 is reversed. Fluid is then transmitted from line 59through valve 58, line 78, centering valve 85, line 76, valve 63 andline 66 to port 69 of motor 67. The return uid is transmitted to tank 50through line 71, valve 63, line 61, valve 58, line 82 and line 83.

When truck motor 10 is employed to actuate the hoisting winch or otherheavy cquipment, it is necessary that the motor be operated at a higherspeed. This is accomplished by manipulation of throttle valve 17 whichadjusts the vair pressure applied to controller 13 through line 21.Controller 13 in turn further opens the valve in carburetor 11 to supplyadditional fuel to motor 10. When motor 10 is operated at these higherspeeds it is important to disconnect hydraulic pump 33. This isaccomplished in accordance with the present invention in an automaticmanner by pressure responsive switch 47. Whenever the pressure in line21 reaches a predeterminedvalue, switch 47 is automatically opened to deenergize solenoid 43. Air pressure is no longer applied 8 to clutch 31so that pump 33 vis disengaged from rotating shaft 30. Alternatively,valve 39 can be a pressure operated valve and line 48 can supplypressure to close valve 39 when the pressure in line 48 exceeds apredetermined value.

In Figure 6 there is illustrated a second embodiment of the rotaryv aircoupling and clutch assembly. The rotary air coupling comprises a sleeve270 which is mounted on shaft 32 by retaining rings 271 and 272. A key,not shown, is provided to prevent sleeve 270 from rotating about shaft32. A longitudinal passage 274 is formed in sleeve 270. One end ofpassage 274 is closed by a plug 275 and the second end is connected to apassage 136' in a spider 135 by a connecting conduit 277. A stationaryannular housing 278 is positioned about sleeve 270. Housing 278 isprovided with an` inlet port 279 which communicates with air line38 ofFigure l. A radial passage 280 is formed in'sleeve 270 such that port279 is in communication with the pneumatically operated clutch throughpassages 280 and 274, conduit 277 and passage 136'.

First and second mating rings 282 and 283 abut a central flanged portionof sleeve 270. O-rings 285 and 286 are positioned between sleeve 270 andrespective rings 282 and 283. Sleeves 287 and 288 engage respectivemating rings 282 and 283 as do respective inserts 290 and 291. Sealingassemblies 293 and 294 are mounted adjacent respective inserts 290 and291.` O-rings 295 and 296 are contained inV housing 278 adjacent thesetwo sealing assemblies. v The sealing assemblies 293 and 294 are of thesame form as assemblies 117 and 120 which are illustrated in Figure 2.Sealing assemblies 293 and 294 are retained in position by respectiveretaining rings 297 and 298. Ball bearing assemblies 299 and 300 areposi tioned between housing 278 and sleeve 270 adjacent respectiveretaining rings 297 and 298. These'ball'bea'ring assemblies are held inposition by respective retaining rings 302 and 303.

Lubricating ports V304 and 305 are formed in housing 278 outsiderespective ball bearing assemblies 299 and 300. Lubricating seals 306and 307 are positioned behousing 278 and sleeve 270 outside'respectiveports 304 and 305. These seals are held in position by respectiveretaining rings 309 and 310. Seal 306 comprises a rst annular housingplate 311 which is fitted against housing 278, and an O-ring 312 ispositioned between these two members. Plate 311 receives an annulardiaphragm 313 which is held in engagement with sleeve 270 at its inneredge by a coil spring 315. The outer edge of diaphragm 313 is engaged bya pair of plates 317 and 318 which are fitted in plate 311. Seal 307 isof the same construction as seal 306. When the rotary air coupling ofFigure 6 is employed, oiler 40 of Figure l is not needed because theball bearing assemblies are lubricated through respective ports 304 and305. The air coupling of Figure 6 has certain advantages in that it canbe readily attached to a shaft without drilling a hollow passagethrough'the shaft. This assembly is particularly useful when it isdesired to actuate individually more than onel device mounted on acommon shaft.

A third embodiment of the air coupling is illustrated in Figure 7. Inthis arrangement the air pressure from line 38 in Figure l istransmitted into the end of hollow shaft 32. A sleeve `member 330 isthreaded into the end of shaft 32 such that the central passage 331 insleeve 330 communicates with the passage in shaft 32. An O-ring 332 ispositioned between shaft 32 and sleeve 330. A cup shaped housing 333encloses sleeve 330 and is spaced therefrom. Housing 333 is providedwith a pair of inlet ports 334 and 335 which communicate directly withthe open end of sleeve 330. Air line 38 of Figure 1 can be connected toeither of these ports, it being understood that the second port isplugged.

A mating ring 337 is abutted against the anged'en'd portion 338 ofsleeve 330. An `Oring 339 is positioned between ring 337 and sleeve 330.An annular insert 9 341 engages matingring 337 and is retainedn positionby a sealing assembly 342 which is identicalto sealing' assembly 117 ofFigure 2. Assembly 342 is retained in position by a ball bearingassembly343 which in turn is held in position by' retaining rings 344and 345 which are fitted into housing 333 and sleeve 330,- respectively.An O-ring 346' is positioned between sealing assembly 342 and housing333. A second sealingnassembly 346, which is identical to assembly 306and 307 of Figure 6, is positioned between sleeve 330 and' housing 333in spaced relationship with ball bearingassembly 343 by means of ai'etainingring 347. A lubricating port 34S is provided in housing 333 tocommunicate with the annular space between sleeve 330 and V'h ousing'333between assemblies 343 and .346. It should be apparent that the aircoupling of Figure 7 functions in substantially the same manner as thecouplings in Figures 2 and 6` except that the air pressureis admitted tothe end of shaft 32 rather than through a -radial opening in the shaft.

From the foregoing description it should be apparent that there isprovided in accordance with this invention an improved control systemforthe operation of power tongs by a hydraulic pump. While this inventionhas been described in conjunction with present preferred ernbodimentsthereof it should be apparent that the invention is not limited thereto.

What is claimed is: i

l. A hydraulic fiuid control system comprising, in combination, avariable vspeed motor, a pneumatically oper ated controller to regulatethe speed of said motor, a source of fluid pressure, first conduit meansto supply fluid pressure to said controller, a throttle valve in saidfirst conduit means, a `hydraulic fluid reservoir, a hydraulic pumpconnected to said reservoir to supply hydraulic fiuid under pressure, afirst drive shaft connected to said pump, a second drive shaft connectedto said motor, a stationary housing enclosing one of said drive shaftsand spaced therefrom, an inlet port in saidhous-v ing, conduit means tosupply fluid pressure to said inlet port, means to interrupt the supplyof fiuid to lsaid inlet port when a predetermined pressure is applied tosaid controller, sealing means disposed between 'said housing and saidone shaft, a fluid passage extending longitudinally of said shaft, oneend of said passage being in communication with said inlet port, aywheel attached to the end of said second'shaft adjacent said firstshaft, a' first annular member attached to the end of said firstV shaftadjacent said flywheel, said first annular member enclosing saidflywheel, an inflatablemember secured to said first annular memberadjacent said "flywheel, the second end of said passage beingin'communication with said infiatable member Vwhereby the application offluid pressure to said inlet port results in' said infiatable memberexpanding to engage said ywheel so that said annular member and saidflywheel rotate together and said pump is energized, a tong base havinga first openingv therein, an annular member mounted on said base, pipegripping jaws attached to said annular member, said member having asecond opening therein whereby a pipe can be introduced into saidmember'tobeengaged by said jaws when said first and second openings arealigned, a hydraulic motor coupled to said annular member to rotate saidmember on said base, avcam attachedv vto said annular member, firstvalved conduit ymeans extending between Asaid hydraulic pump andsaidvhydraulicmotor to rotate said hydraulic motor in a first direction, avalve body defining a piston chamber, a first port in said valve bodycommunicating lwith said piston chamber intermediate the ends thereof, asecond' 'port at said valve body communicating with said piston chamberintermediate the ends thereof, a piston ldisposed in said pistonchamber, said piston having a recess therein whereby said `first andlsecond vports are incommunication when said piston occupies a firstposition in saidpiston. chamber, means urging said piston towardone'endfof said pi'stonchamber whereby said first and second portsI areseparated by said piston, second conduit means extending between saidfirst port and said one e'nd of said piston chamber whereby fluidpressure appliedv to said port tends to overcome said urging means tomove said piston to said first position, means extending fromv saidpiston externally of said valve body whereby a force applied theretoresults in said piston being moved toward said first end of said pistonchamber, said valve body being positioned whereby said cam engages saidlast-mentioned means when said first and secondV openings are aligned,third valved conduit means extending between said pump and said firstport, and fourth conduit means extending between said second port andsaid motor Vfor rotating said hydraulic motor in a second direction.

2. A hydraulic fluid actuated power tong system com-` prising, incombination, a tong base having a first opening therein, an annularmember mounted on said base, pipe gripping jaws attached to said annularmember, said member having a second opening therein whereby a pipe canbe introduced into said member Vto be en- Vgaged by said jaws when saidfirst and second openings are aligned, a hydraulic motor coupled to saidannular member to rotate said member on said base, a cam attached tosaid annular member, a hydraulic fiuid reser- Voir, a hydraulic pumpconnected to said reservoir to supply hydraulic iiuid under pressure,first valved conduit means extending between said hydraulic pump andsaid hydraulic motor to rotate said hydraulic'motor in a firstdirection, a valve body defining a piston chamber, a first port in saidvalve body communicating with said piston chamber intermediate the endsthereof, a second port at said valve body communicating with said pistonchamber intermediate theends thereof, a piston disposed in said pistonchamber, said piston having a recess therein whereby said first andsecond'p'orts are in communi cation when said piston occupies a firstposition in said piston chamber, means urging said piston toward one endof said piston chamber whereby said first and second ports are separatedby said piston, second conduit means extending between said first portand said one end of said piston chamber whereby fluid pressure appliedto said first port tends to overcome said urging means to move saidpiston to said first position, means extending from said pistonexternally of said valve body whereby a force applied thereto results insaid piston being moved toward said first end of said piston chamber,said valve body being positioned whereby said cam engages saidlast-mentioned means when vsaid first and second openings are aligned,third valved conduit means extending between said pump and said firstport, and fourth conduit means extending between said second port andsaid motor for rotating said hydraulic motor in a second direction.

3. A controlsystem to prevent a driven member from being operated atexcessive speeds compri-sing, in combination, a variable speed drivingmember, a driven member, a first drive shaft connected to said drivingmember, a second drive shaft connected to said driven member, apneumatically operated clutch to connect said first and second shaftswhen energized, conduit means to supply fluid pressure to said clutch, avalve in said conduit means, and means responsive to the speed ofoperation of said driving means to aotuate said valve when the speed ofoperation of said driving means exceeds a predetermined value, saidclutch thereby being deenergized.

4. The combination inaccordance with claim 3 wherein said clutchcomprises expansible means positioned between said first and secondshafts, said expansible means being secured to one of said shafts and`adapted to engage the other of said shafts when duid pressu-re isapplied thereto, and means forming a part of said conduit means to-apply fluid pressure to said expansible means.

i 5. The combination -in accordance with claim 4 wherein said means'forming a part of said conduitmeans com prises a stationary housingenclosing said one shaft, said assenso housing having an inlet portcommunicating with said conduit means, means defining a passageextending at least in part longitudinally of said shaft, and rotarysealing means extending between said housing and said one shaft to forma chamber between said one shaft and said housing, said chamber being incommunication with said port and one end of said passage, the second endof said passage being in communication with said expansible means.

6. The combination 1in accordance with claim 5 wherein said passageextending longitudinally of said one shaft is formed within said oneshaft, 'and wherein a second passage is formed in said one shaft betweensaid chamber and said first mentioned passage.

7. The combination in accordance with claim wherein said passageextending longitudinally of said one shaft is external of said oneshaft.

8. The combination in accordance with claim 3 wherein said clutchcomprises a flywheel attached to the end of one of said shafts adjacentthe other of said shafts, an annular member attached to the end of theother of said shafts adjacent said one shaft, said annular memberenclosing said ywheel, an inflatable member secured to said annularmember adjacent said flywheel, and means communicating with saidinflatable member to supply fluid pressure thereto whereby saidinflatable member expands to engage said flywheel so that said annularmember and said flywheel rotate together.

9. A pump speed control system comprising, in combination, a variablespeed motor, a pneumatically operated controller to regulate the speedof said motor, first conduit means to supply fluid pressure -to saidcontroller, a throttle exceeds a predetermined value, said clutchthereby being 4 deenergized.

l0, The combination in accordance with claim 9 wherein said -secondvalve is electrically operated and wherein said last-mentioned meanscomprises a pressure ope-rated electrical switch in communication withsaid first conduit means, said switch being connected in circuit withsaid second valve.

l1. A rotary air coupling to transmit fluid pressure from a stationaryfluid line to a device mounted on a rotatable shaft comprising, incombination, a shaft, a stationary housing enclosing said shaft andspaced therefrom, an inlet port in said housing, sealing means disposedbetween said housing and said shaft, and means defining a fluid passageextending longitudinally of said shaft, one end of said passage being incommunication with the 4interior of said housing adjacent said inletport.

l2. A rotary coupling 4to transmit fluid pressure from a. stationaryfluid line to a device mounted on a rotatable shaft comprising, incombination, a shaft, a stationary housing enclosing said shaft and:spaced therefrom, an inlet port in said housing, first sealing meansdisposed between said housing and said shaft on one side of said por-t,second sealing means disposed between said housing and said shaft on theother side of said port, and means defining a fiuid passage extendinglongitudinally of said shaft, one end of said passage being incommunication with the region between said two sealing means which is incommunication with said port.

13. A rotary coupling to transmit fluid pressure from a stationary fluidline to a device mounted on a rotatable shaft comprising, incombination, a shaft, a stationary annular housing enclosing said shaftand spaced therefrom, an inlet port in said housing, a pair of spacedbearing assemblies positioned between said housing and said 'shaft topermit rotation of said shaft within said housing, first sealing meansdisposed between said housing and said shaft on one side of said port,second sealing means disposed between said housing `and said shaft onthe other side of said port, and means defining a uid passage extendinglongitudinally of said shaft, one end of said passage being incommunication with the region between said two sealing means which is incommunication with said port.

14. The combination in accordance with claim i3 wherein each of 4saidsealing means comprises a mating r-ing in fluid tight engagement withsaid shaft, an annular casing in fiuid tight engagement with saidhousing, a U- shaped annular packer in -said casing, an expansion ringengaging said packer to force saidV packer into engagement with saidcasing when fluid pressure is introduced into said housing through saidinlet port, and an annular insert disposed between said mating ring andsaid casing, said insert being in fluid tight engagement with saidcasing and making slidable fluid tight contact with said mating ring.

l5. A rotary coupling to transmit fluid pressure from a stationary fluidline to a device mounted on a rotatable shaft comprising, incombination, a shaft having a passage therein extending longitudinallythereof, a stationary annular housing enclosing said shaft and spacedtherefrom, an inlet port in said housing, a pair of spaced bearingassemblies positioned between said housing and said shaft to permitrotation of said shaft within said housing, first sealing means disposedbetween said housing and said shaft on one side of said port, secondsealing means disposed between said housing and said shaft on the otherside of said port, and means defining a passage between the passage insaid shaft and the region between said two sealing means which is incommunication with said port.

16. A rotary coupling to transmit fluid pressure from a stationary fluidline to a device mounted on a rotatable shaft comprising, incombination, a shaft, Va sleeve attached to and enclosing said shaft,said sleeve having a passa-ge formed therein extending longitudinally ofsaid shaft, a stationary housing enclosing said sleeve and spacedtherefrom, an inlet port in said housing, first sealing means disposedbetween said housing and said shaft on one side of said port, secondsealing means disposed between said housing and said shaft on the otherside of said port, and means vdefining a passage between the passage insa-id sleeve and the region between said two sealing means which is incommunication with said port.

17. A rotary coupling to transmit uid pressure from a stationary fluidline to a device mounted on a rotatable shaft comprising, incombination, a shaft, a sleeve attached to and enclosing said shaft,said sleeve having a passage formed therein extending longitudinally ofsaid shaft, a stationary housing enclosing said sleeve and spacedtherefrom, an inlet port in said housing, first sealing means disposedbetween said sleeve and said housing on one side of said port, a firstbearing assembly disposed between said sleeve and said housing on saidone side of said port farther from said port than is said first sealingmeans, second sealing means disposed between said sleeve and saidhousing on said one side of said port farther from said port than issaid first bearing assembly, a second port in said housing between saidfirst bearing assembly and said second sealing means, third sealingmeans disposed between said sleeve and said housing on the second sideof said first-mentioned port, a second bearing 'assembly disposedbetween said sleeve and said housing on said second side of saidfirst-mentioned port farther from said first-mentioned port than is saidthird' sealing means, fourth sealing means disposed between said sleeveand said housing on said second side of said first-mentioned portfarther from said first-mentioned port than is said second bearingassembly, a third port in said housing between said second bearingassembly 13 and said fourth sealing means, and means defining a passagebetween the passage in said sleeve and the region between said first andthird sealing means which is in communication with said first-mentionedport.

18. A rotary air coupling to transmit uid pressure from a stationaryfluid line to a device mounted on a rotatable shaft comprising, incombination, a hollow shaft,`

a cup-shaped stationary housing enclosing one end of said shaft inspaced relation therewith, first sealing means dis- 'l posed betweensaid housing and said siaft, an inlet port in said housing between saidfirst sealing means and said one-end of said shaft, a bearing assemblybetween said housing and said shaft further from said one end of saidshaft than is said first sealing means, second sealing means disposedbetween said housing and said shaft in spaced relation with said bearingassembly yand further from said one end of said shaft than is saidbearing assembly, andk a second port in said housing between saidbearing assembly and said second sealing means.

19. The combination in accordance with claim 18 wherein said firstsealing means comprises a mating ring in fiuid tight engagement withsaid shaft, an annular casing in fiuid tight engagement with saidhousing, `a U- shaped annular packer in said casing, an expansion ring vengaging said packer to force said packer into engagement with saidcasing when fiuid pressure is introduced into said housing through saidinlet port, and an annular insert disposed between said mating ring andsaid casing, said nular member, a cam attached to said annular member, asource of hydraulic fluid under pressure, first valved conduit meansextending between said source of fiuid and said motor for rotating saidmotor in a first direction, a valve body defining a piston chamber, afirst port in said valve body communicating with said piston chamberintermediate the ends thereof, a second port in said valve bodycommunicating with said piston chamber intermediate the ends thereof, apiston disposed in said piston chamber, said piston having a recesstherein whereby said first and second ports are in communication whensaid piston occupies a first position in'said piston chamber, meansurging said piston toward one end of said piston chamber whereby saidfirst and second ports are sepinsert being in fluid tight engagementwith said casing and making slidable fiuid tight Vcontact with saidmating ring.

20. A valve comprising, in combination, a valve body defining a pistonchamber, a first port in said valve body communicating with said pistonchamber intermediate the ends thereof, a second port in said valve bodycommunicating with ysaid piston chamber intermediate the ends thereof, apiston disposed in said piston chamber, said piston having a recesstherein whereby said first and second ports are in communication whensaid piston occupies a first position in said piston chamber, meansurging said piston toward one end of said piston chamber whereby saidfirst and second ports 'are separated by said piston, conduit meansextending between said first port and said one end of said pistonchamber whereby fluid pressure applied to said first port tends toovercome said urging means to move said piston to said first position,and means extending from said piston externally of said housing wherebythe application of fonce thereto results in said piston being movedtoward said first end of said piston chamber.

2 1. A valve comprising, in combination, a base having a central passagetherethrough, a piston chamber secured to said base, said piston chamberhaving first and second ports therein intermediate the ends thereof, apiston disposed in said piston chamber, said pistonV having a recesstherein whereby said first and second ports arein communication whensaid piston occupies a first position in said piston chamber, a memberpositioned in the passage of said base for movement therein, said memberextending v to a region exterior of said base, a spring urging saidmember into engagement with said piston to move said piston toward oneend of said piston chamber whereby said first and second ports areseparated by said piston, said piston chamber having a passage formedtherein between said first port and saidfone end of .said chambenand aplate secured'to saidfpiston chamber to cover said one end thereof.

22. A hydraulic uid actuated power tong system. comprising, incombinatiomfa base having a firstlopening l therein, an annular membermounted on said base, pipe gripping jaws attached tosaid annularmember',V said member having a second opening therein whereby a pipe canbe'inserted to be engaged'by said jaws when said first andfsecondopenings are ,a1igned a hydraulicI motor coupledto said annular memberfor4 rotating said an-Y arated by said piston, second conduit meansextending between said first port and said one end of said pistonchamber whereby fluid pressure applied to said first port tends'toovercome said urging means to move said piston to said first position,means extending from said piston externally of said valve body wherebythe application of force thereto results in said piston being movedtoward said first end of said piston chamber, said valve body beingpositioned whereby said cam engages said last-mentioned means when saidfirst and second openings are aligned, third valved conduit meansextending between said source of fiuid and said first port, and fourthconduit means extending between said second port and said motor forrotating said motor in a second direction.

23. The combination in accordance with claim 22 wherein said first andthird valve conduit means comprise a first conduit connected at one endto said source of fluid under pressure; a first valve having first,second, third and fourth openings therein, said first and fourthopenings being in communication and said second and third openingsVbeing in communication when said first valve is in a rst position, saidfirst and second openings being in communication and said third andfourth openings being in communication when said first valve is in asecond position; a second valve having fifth, sixth, seventh and eighthopenings therein, said fifth and eighth openings being in communicationand said sixth and seventh openings being in communication when saidsecond valve is in a first position, said fifth and sixth openings beingin communication and said seventh and eighth openings being incommunication when said second valve is in a second position; the secondend of said first conduit being connected to said second opening; asecond conduit extending between said third and sixth openings; a thirdconduit extending between said seventh opening and a terminalof saidmotor; a fourth conduit extending between said fifth opening and thesecond terminal of between said first opening and said first port.

References Cited in the file of this patent UNITED STATESIPATENTS1,126,124 Strite et al. Jan. 26, 1,846,578 Bates -Feb. 23, 19322,398,087 Dodge Y Apr. 9,'1946 2,450,934 Calhoun p Oct. 12, 19482,544,639. Calhoun Mar. 13, 1951 2,550,045 a De Hetregca 'Apr. 24, 19512,556,536 Harris L June. 12, `1951 2,578,686V Fish y. Q-Dec. 18, 1951 k2,615,681 True Oct. 28,l 1952 2,639,894 Smith n n "May 26,1953

Gardner Mar. 1,

